I owned CS6 speakers for about 10 years. The Onkyo could be used a stop gap as mentioned above but I wouldn't play it at ear splitting levels because I'm sure it would clip. The CS6 needs a high quality powerful amp to sound its best. Amps that have about 200 or more watts/ch at 8 ohms and double that power at 4 ohms would be a starting point. I used a Classe SS amp that was rated for 400 w/ch at 8 ohms and 800 w/ch at 4 ohms along with a tube preamp. If I had to do it over again, I'd probably go with a different SS amp and a slightly warm tube preamp.
would using the onkyo a9150 with Thiel CS6 speakers be safe?
The onkyo receiver says it has this but it's only 60 watts per channel My krell fpb300cx failed and somebody loaned me this receiver. Onkyo has this description about current.
Customized High-Current Transformer and Custom Audio-Grade Capacitors
Current has great influence on sound quality. High current is required for a better grip on the speaker transducers, improving control and accuracy.
A customized high-output transformer and two huge custom capacitors inside the A-9150 deliver current through discrete output-stage transistors that are kept cool by an aluminum heat sink.
Speakers react instantly, with throw-range precisely controlled for accurate articulation even through dynamic and complex musical passages.